The invention relates to a connecting seam between two thin-walled sheet-metal parts.
A connecting seam is known from DE1952300584. Such a configuration of a laser weld seam has basically proven its worth. However, it has been repeatedly shown that one of the two sheet-metal parts involved in the laser weld seam has local sink marks in a visible area of the vehicle body. Such sink marks are unacceptable surface defects that adversely affect the visual appearance of the vehicle body. Such sink marks must be removed during manual refinishing works before a vehicle body is painted. This is time-consuming and cost-intensive. In some cases, computer tomography test (CT scans) found cracks in the flange region of one of the metal sheets.
FIG. 5 shows an example of a laser soldered seam according to the prior art. FIG. 5 shows schematically a connecting seam 100 which connects two thin-walled sheet-metal parts 200, 300 and is arranged in a flange region of two adjacent flange portions 200′, 300′ while forming a joining zone F. In such a configuration of the connecting seam 100, the presence of thermally induced shear stress, in particular in the sheet-metal part 300 with obtuse flange portion 300′, can cause sink marks E, which is unwanted.